Table 1.
Important features for classification (ranked).a
| Subreddit | Positive coefficients | Negative coefficients |
| r/EDAnonymous | ed, restrict, purg, bing, calori, LIWCb ingestion, fast, recoveri, eat, ate | bpd, anxieti, addict, diagnos, drug, substance use lexicon, ptsd, LIWC work, LIWC health, med |
| r/addiction | addict, clean, smoke, rehab, sober, drug, weed, relaps, use, guns lexicon | bpd, diagnos, ptsd, adhd, therapi, isolation lexicon, LIWC hear, therapist, post, LIWC work |
| r/adhd | adhd, adderal, add, vyvans, focu, forget, final, LIWC work, medic, came | bpd, ptsd, hurt, therapi, guess, suicidality lexicon, fear, bodi, suicid, pain |
| r/alcoholism | sober, alcohol, drink, withdraw, drunk, LIWC nonfluencies, drank, meet, beer | drug, weight, therapi, adhd, medic, isolation lexicon, notic, attack, dure, addict |
| r/anxiety | anxieti, wa dead, LIWC negative emotion, LIWC money, anxiou, LIWC motion, LIWC numbers, panic attack, anxious | ptsd, bpd, adhd, LIWC ingestion, LIWC articles article, addict, kill, substance use lexicon, LIWC body, social |
| r/autism | autism, autist, spectrum, son, game, diagnos, function, diagnosi, explain, interest | ptsd, bpd, addict, LIWC health, disord, adhd, med, 2, stay, guns lexicon |
| r/BipolarReddit | bipolar, manic, mania, lithium, mood, episod, psychiatrist, hospit, LIWC money, med | adhd, addict, bpd, ptsd, LIWC ingestion, LIWC anxiety, LIWC work, automated readability index, LIWC future tense |
| r/bpd | bpd, fp, LIWC numbers, LIWC inclusive, LIWC negative emotion, LIWC sadness, bad, drug, LIWC affective processes, feel | ptsd, adhd, weight, LIWC articles article, LIWC health, addict, LIWC 1st pers, anxious, food, isolation lexicon |
| r/depression | depress, LIWC sadness, LIWC negations, gunning fog index, LIWC positive emotion, LIWC family, cri, LIWC feel, bed, LIWC total pronouns | bpd, symptom, ptsd, adhd, food, isolation lexicon, LIWC conjunctions, diagnos, addict, n sents |
| r/healthanxiety | cancer, LIWC biological, health anxieti, LIWC health, health, LIWC body, test, fine, LIWC assent, googl | ptsd, adhd, bpd, addict, emot, disord, LIWC 3rd pers, LIWC social processes, social, mental |
| r/lonely | lone, loneli, isolation lexicon, messag, LIWC certainty, friend, girl, LIWC positive emotion, sit, LIWC religion | LIWC anxiety, ptsd, addict, bpd, suicidality lexicon, symptom, therapist, abus, suicid, med |
| r/ptsd | ptsd, trauma, flashback, trigger, nightmar, sexual, domestic stress lexicon, abus, tire, guns lexicon | bpd, addict, drink, adhd, LIWC health, isolation lexicon, LIWC work, disord, LIWC certainty, LIWC sadness |
| r/schizophrenia | schizophrenia, hallucin, delus, schizophren, voic, paranoid, LIWC religion, hospit, ill, LIWC tentative | adhd, ptsd, bpd, addict, abus, flesch kincaid grade level, isolation lexicon, LIWC body, LIWC biological, LIWC health |
| r/socialanxiety | social anxieti, nervou, walk, awkward, girl, group, convers, speak, face, anxieti | bpd, adhd, ptsd, LIWC health, addict, diagnos, suicid, LIWC sadness, support |
| r/SuicideWatch | suicidality lexicon, suicid, LIWC negations, death, kill, want die, LIWC sadness, LIWC friends, LIWC money, plan | bpd, symptom, anxious, substance use lexicon, usual, LIWC 2nd pers, smog index, isolation lexicon, weight, attack |
aTheir presence makes it more (positive) or less (negative) likely the classifier will predict the subreddit. Individual word stems are obtained from term frequency–inverse document frequency.
bLIWC: Linguistic Inquiry and Word Count.